[求助]新手求助~（关于初级的神经网络问题） [复制链接]

各位大虾，我在网上看到的教程里的一个程序段，本来想要试试看的： 00Ye ]j_  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); SU~ljAF4  
net.trainParam.show = 50; ^p%3@)&  
net.trainParam.lr = 0.05; ojIGfQV  
net.trainParam.epochs = 300; `'bu8JK  
net.trainParam.goal = 1e-5; <hgfgk7<  
p = [-1 -1 2 2;0 5 0 5]; o6:]Hvqjr  
t = [-1 -1 1 1]; "p>kiNu  
net=train(net,p,t); uF D  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 hb)8
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TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 =%[vHQ\%  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 $JK,9G[Vu  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 2ryg3%+O  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 bl|)/)6o  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 TD!c+${w  
TRAINGD, Performance goal met. 7Mh!@Rd_V  
a = sim(net,p) "1Y DT-I"  
plot(p,t,p,a,'o') Vk1 c14i>  
但是为什么老是报错：  bWZzb&  
??? Input argument "net" is undefined. uxW<Eh4H*